Stringed musical instrument



Dec. 6, 1938. R. DQPYERA 2,138,907

STR INGED MUS I CAL INS TRUMENT Filed June 24, 1935 3 Sheets-Sheet l Dec. 6, 1938. R. DOPYERA STRINGED MUSICAL INSTRUMENT Filed June 24, 1935 5 Sheets-Sheet 2 INVENTQR. RuDoL PH OPYLRA.

ATTGRN E Y.

Dec. 6, 1938. R. DoPYi-:RA 2,138,907

STRINGED MUSICAL INSTRUMENT Filed June 24, 1955 3 Sl'leets--Sheerl 3 INVENTOR.

UDOL PH OPYERA.

l/l ATTORNEY.

Patented Dec. 6, 1938 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to improvements in ment I comprises a metal body I2, a neck I3,

stringed musical instruments.

'I'he general object of the invention is to provide a stringed instrument including a novel diaphragm and electrical pick-up device.

Another object of the invention is to provide an improved body for a stringed instrument.

A further object of the invention is to provide a novel mounting for a pick-up device in a stringed musical instrument.

Other objects and the advantages of this invention will be apparent from the following description taken in connection with the accompanying drawings, wherein:

Fig. 1 is a top plan view of a stringed musical instrument embodying the features of my invention;

Fig. 2 is an enlarged section taken on line 2--2 of Fig. 1;

Fig. 3 is a fragmentary side view of the guitar shown in Fig. 1;

Fig, 4 is a fragmentary enlarged section taken on line 4--4 of Fig. 1;

Fig. 5 is a view similar to Fig. 4 showing a modied form of body joint;

Fig. 6 is an enlarged fragmentary section taken online 6-6 of Fig. 1;

Fig. 7 is an enlarged fragmentary section taken on line 'I-l of Fig. 3;

Fig. 8 is an enlarged fragmentary section taken on line 8-8 of Fig. 1;

Fig. 9 is an enlarged fragmentary top plan view of the guitar shown in Fig 1 with the cover and tail piece removed;

Fig. l0 is a bottom plan View of the electrical pick-up unit on a reduced scale;

Fig. 11 is a view similar to Fig, 8 showing a modied type of diaphragm;

Fig. 12 is a view similar to Fig. 8 showing the electric pick-up unit mounted in a different manner;

Fig. 13 is a diagrammatic view showing the method of wiring the electrical pick-up unit;

Fig. 14 is a fragmentary view similar to Fig. 8

showing a modified electric pick-up unit in another mounting, and

Fig. l5 is a section taken on line |5-I5 of Fig. 14.

This invention is a continuation in part of my copending application, Serial No. 720,753, filed April 16, 1934, now Patent No. 2,045,265, granted June 23, 1936.

Referring to the drawings by reference characters I have indicated my improved musical instrument generally at I0. As shown the instruand a tail piece I4. The neck includes a thickened portion Il* which is reduced in depth and width as at I4b to provide an extension |4 and a shoulder Md. The extension I 4c passes through a slot Ile in the side wall at one end of the body and the shoulder I4d engages the front portion of the side wall as at I 4f. In this manner, that is by the engagement of the extension I4c in the slot He and the engagement of the shoulder |11d with the front portion 0f the side wall the forward end of the neck piece is firmly secured in place (see Figs. 7 and 8).

The body I2 comprises a peripheral wall I5, a bottom member I6 and a top member Il all preferably made of metal.

As clearly shown in Fig. 4, portions adjacent the top and bottom of the side wall I5 are set inward to form a top portion I8 and a bottom flange portion I9. The side Wall I5 further includes a plurality of spaced panels 20 which are shown as inwardly directed and which serve to stiifen the side Wall I5.

The edge portion of the bottom I6 is rolled upward and inward to form a bead 2| and includes an upwardly extending portion to form a flange portion 2|. The edge portion of the top Il is rolled downward and inward to form a bead 22 and includes a depending portion to form a iiange portion 22'.

When assembling the instrument the flange portions 2| and 22 are positioned against the outer surface of iianges I8 and I9 of the wall |5 and adjacent to shoulders 23 at the end of the ilange portions I8 and I9, and then the anges 2|' and 22' are preferably spot welded to the flanges I8 and I9 as at 2|" and 22". Or if desired the liquid solder may be applied to the inner surfaces of the flanges 2| and 22' before they are positioned in place on the side wall I5.

In Fig. 5 I have shown a modified method oi securing the top |I and the bottom I6 to the side wall I5. In this View the flange portions of the side wall I5 are directed outwardly as indicated at I8' and I9' and the ilanges 2| and 22" are positioned inside of the side wall flanges and adjacent to shoulders 23 at the ends of the flanges 2| and 22' and may be secured as previously described.

The top member I'I includes an upper portion 25 which has a recess 25 therein, the side Wall 26 and bottom wall 2l of which are preferably formed integral with the upper portion 24. In the bottom of the recess 25 a recess 28 is provided which includes a wall 29 which is integral with the bottom 21 of the recess 23. 'Ihe lower edge of the wall 23 is turned inward to form a flange 33 which in turn forms a central aperture 3|.

If desired a well member 32 which is made of sheet metal may be positioned between the bottom I3 and the nadie/33. ,As shown the well member 32 includes a side wall 33 having at its upper portion an inturnednange 34 and at its lower portion a similar inturned flange 35. Ihe well iiange 34 is soldered or otherwise secured to the flange 33 as at 34 and the well ilange 35 is soldered or otherwise ilrmly secured to the bottom I3 as at 35'.

In the upper portion 24 of the top member I1 intermediate the recess 25 and the neck I3 I have shown a plurality oi apertures 33 and a plurality of reduced apertures 31. As shown in Fig. 3 the apertures 36 are formed by drawing inward the metal of the top portion to form downwardly extending collars 33 from which extend a plurality of ribs 39 which are integral with the side walls 38. The reduced apertures 31 are formed by punching out the material of the top portion.

At the neck end of the top member I1 I provide an inclined portion 43. (See Figs. 7 and 8.) As shown the key board portion 40 is formed by pressing the material of the upper portion 24 upward a predetermined distance from the neck end and inclining it inwardly towards the edge of the body.

Positioned in the recesses 25 and 23 I provide a metal diaphragm 4I which includes a concave portion 42 and a convex central portion 43. 'Ihe outer edge of the diaphragm includes a foot flange 44 which rests on the iiange 21. For supporting a bridge member 45 I provide a spider member 46 which includes a plurality of radial legs 41 which rest on the upper ends of a plurality of inwardly pressed portions 43 provided on the diaphragm 4I. At the apex of the convex portion 43 of the diaphragm a nut 43 is secured thereto which is engaged by a bolt 53 which passes through the spider member.

Positioned over the spider member 46 I provide a cover member 52. As shown the cover member 52 is made of sheet metal and includes a top portion 53 which in general is upwardly inclined from its outer edge towards the center (see Fig. 8). The diameter of the top portion 53 is greater than the diameter of the recess 25 in the body. At the periphery of the cover member the material of the top portion 53 is bent inwardly to form a seat portion 54 and then bent downwardly to form a iiange 55. The seat portion 55 of the cover is adapted to engage the outer face of the upper portion 24 of the top member I1 and the flange 55 is adapted to frictionally engage the inner face of the side wall 23 of the recess 25.

Adjacent the center of the cover 52 I provide a raised bridge portion 53 which is integral with the top portion 53 and includes side walls 51, end walls 58 and a top portion 53. The side walls 51, end walls 53, and the top 53 form a chamber 63 in which the bridge 45 is positioned. The side walls 51 are steeply inclined to meet the top portion 53 (see Fig. 8) while the end walls 53 are gradually sloped to meet the top portion adjacent the periphery of the cover (see Fig. 2). Each of the side walls 51 has an aperture 6I therein through which the playing strings 62 pass.

For securing the cover 52 in position I provide a plurality of bolts 66 each of which is positioned in an aperture provided in a depreed portion 33 of the cover. (See Fig. 6.) Each of the bolts 66 is positioned in an aperture 33 in the top member I1 and engage a nut 13 which is secured to the top member as by soldering it thereto as at 13. The cover 32 further includes a plurality of apertures 1I which may be shaped and spaced to form a pleasing design. (See Fig. l.)

Within the body I2 at the end oppodte the neck I3 I provide a wood block 12 which is preferably shaped to snugly nt the contours oi the body. (See Figs. 3 and 9.) A portion 13 of the neck I3 extends into the body I2 and abuts against the block 12. For securing the neck portion 13 to the block 12 I provide a metal angle member 14 one ange 15 of which engages the upper face of the neck portion 13 and the other ilange 13 of which engages the inner face of the block 12. The ange 13 is suitably apertured to receive the counter-sunk head of a bolt 11 which is positioned in a suitable aperture provided in the neck portion 13 and is engaged by a nut 13 which clamps against the under face of the neck portion 13. The flange 13 is suitably apertured to receive a bolt 13 which extends through a suitable aperture provided in the block 12 to a distance beyond the outer tace of the body I2. In the wall Il and the block 13 I provide a recess 33 in which a nut 3| is positioned and engaged by the bolt 13 to nrmly clamp the angle member 13 to the block 12.

The tail piece I4 is suitably apertured to allow the bolt 13 to pass therethrough and beyond the tail piece I4 I provide a nut 32 which firmly clamps the tail piece tothe body I2. Furthermore, the tail piece I4 preferably includes a downwardly extending boss 34 which engages the cover 52 (see Fig. 8) thus relieving the bridge 43 of the entire pressure of the strings 32.

Positioned in the diaphragm 4I, I provide an electrical pick-up device which is indicated Lenerally at 35. As shown the device 35 includes a permanent magnet 33 of the horse-shoe type which is substantially circular (see Figs. 9 and l0) with the pole ends thereof extending outwardly as indicated at 31. To prevent the pole ends from vibrating when the instrument is played I position a bar 33 of non-ferrous material across the outer faces o f the pole ends and a bar 33' o! simi lar material against the inner portion of the magnet 33 and clamp the bars 33 and 33 together with a bolt 33 which is also made of non-ferrous metal.

Positioned on the magnet 35 at each pole thereof I provide a magnet 33, the core 33 of which is connected to its associated pole of the magnet 36. Below the diaphragm 4I I provide a plurality of brackets 33" which are secured to the bottom I6 by soldering or spot welding them thereto as at 30. Posts 3I mounted on the brackets 33" extend through apertures 32 provided in the diaphragm 4I and support the magnet 33. The magnet 36 is secured to the brackets 33" by bolts 33 which pass through the magnet and the posts. The posts 3I and the bolts 33 are made of nonferrous material. In the body I2 adjacent the bolt 13 I provide a jack plug 34, (see Fig. 9) the plug opening of which is accessible from the exterior of the body.

As diagrammatically shown in Fig. 13 one end of each oi the coils oi' the magnets is connected by a wire 35. The opposite end of-one of the coils is connected by a wire 33 to one terminal of the plug 94 and the opposite end of the other coil is connected by a wire 31 to the other terminal of the plug. In use a jack 33 which is suitably wired to a radio amplifying unit 33 which in turn is suitably wired to a loud speaker |33 is inserted in the plug 34.

In Fig. 11 I have shown a modified diaphragm |02. The diaphragm |02 is similar to one shown and described by me in my co-pending application, Serial No. 693,111, filed October 11, 1933, now Patent No. 2,029,496, granted February 4, 1936 and in general includes a raised convex portion |03 which merges into a central concave portion |04'. Adjacent its periphery the diaphragm |02 includes a foot portion |05 which rests on the flange instead of on the flange 21 like the diaphragm 4|.

When the diaphragm |02 is used the permanent magnet 86 of the electric pick-up unit 85 is of larger diameter than when the diaphragm 4| is used but otherwise the pick-up unit is similar. The diaphragm |02 like the diaphragm 4| is provided with apertures |05 through which the posts 9| project.

In Fig. 12 I have shown an instrument similar to that previously described but wherein the electric pickup unit is positioned in the body |2 intermediate the diaphragm well and the neck end of the body. The neck is eut away within the body as at |05' to provide space for mounting the pick-up unit.

In Fig. 15 I have shown another type of dia-` phragm |06 mounted in my improved instrument. In general the diaphragm |06 lincludes a raised convex portion |01 having adjacent its periphery a foot portion |00 which rests on the flanges 30.

Furthermore in Figs. 14 and 15 I have shown a modified form of electric pick-up unit indicated generally at |09. As shown the pick-up unit |09 includes a permanent magnet |09 of the horseshoe type and which is similar to the magnet 86 of the pick-up unit 85. The magnet |00 is secured to a non-ferrous base member |0 by screws and the base ||0 in turn may be secured to the bottom I6 of the guitar as by soldering or spot welding it thereto as at III'. Positioned on the magnet |09 at each pole thereof I provide an electro-magnet coil ||2 which includes a core member ||3. The core member ||3 is shown as cylindrical in cross section and extends below the magnet ||2 and is positioned in an aperture ||4 in the magnet |09. The lower portion of the core |l3 is threaded as at Il! to engage in a similarly threaded aperture ||6 in the base ||0.

Each core I3 extends upwardly from the magnet I 2 and passes through an aperture l I1 in the diaphragm |06 and an aperture IIB in the cover 52. On the upper end of each core ||3 I provide a cross bar portion ||9 which extends transversely of the strings 62 and is positioned therebelow. 'Ihe cross bars l|9 are disposed just below the strings 62 and the cross bars can be turned slightly by means of a wrench applied thereto so that their positions beneath the strings will be varied and thus the tone control may be varied. In the modification shown in Figs., 14 and 15 the neck portion 13 terminates at the front of the well member 32 as shown.

It will be understood that the electro-magnet pick-up units described may be positioned either above or below the diaphragm at any point between the string bridge and the string tension keys.

From the foregoing description it will be apparent that I have invented a novel musical in strument and electric pick-up which can be economically manufactured and which is highly ei*- iicient in use.

Having thus described my invention, I claim:

1. A musical instrument having a base, side walls and a top, forming a hollow body, said top having an aperture therein, a diaphragm in said hollow body, said diaphragm having an aperture therein, strings disposed above the top of said body, a pickup unit having a core on the interior of said body and secured to the base thereof, said core extending upwardly through the apertures in said diaphragm and said top and terminating below said strings.

2. A musical instrument comprising a base, side walls and a top forming a hollow body, a raised convex diaphragm secured to the interior of said body substantially centrally thereof, said diaphragm having an aperture in the wall thereof, said top having an aperture therein in alignment with the aperture in the diaphragm, strings disposed above the top of said body. and a pickup unit having a core on the interior of the body extending through the apertures in the diaphragm and the top and terminating adiacent the strings.

RUDOLPH DOPYERA. 

